Pros: Lots of space, instrument separation, depth, huge sound stage, highs that are not piercing(does not hit the wall of comfortable listening, so small

Cons: None for me, life is way too short to grumble about the price. It is cheaper than competing brands!

I am lost for words for 2 reasons, 1st: These in ears behave much more like over ears headphones in all the good ways.
2nd: these deserve to be much more popular than they are, I am simply shocked that there is not much more renowned!
I currently own the Shure SE535's as well as Sennheiser IE8 and have used and owned many of the 500 and under earphones, such as Monster Turbine Copper Pro and Etimotics. all these earphones are very good and each of them has qualities that are admirable and impressive, however what the Grado GR10 has is something that I don't think could be measured and or described in words, all I can say is that regardless of specs these in ears make music! this...

These IEMs are not jack of all trades, which means they do not perform like their main rivals in the price range (300-500 dollars).
Most IEMs in this price range, such as UEs, shures or Westones use multiple balance armatures to produce a relatively good sound through all range, the GR10, on the other hand, uses single armature, there is a inherit disadvantage of this design, as one single armature cannot cover the whole range as good as the multiple ones. In the light of this, the GR10 lacks treble and bass energy and extension which most of it's rivals possess. I did not mean the treble and bass quality aren't good, both of them are well controlled and of high quality. The...

Pros: They've managed to capture the Grado headphone sound with these little babies.

Cons: Isolation. The tips are kind of small "than they should be," at least for some people.

Gear used for testing: iPod Video 80gb (5th gen, Rockbox) + Fiio E17
Test tracks: "Survival" by Muse, "Take the Power Back" by Rage Against the Machine, "Finally Free" by Dream Theater, "Hessian Peel" by Opeth, "Sacred Worlds" by Blind Guardian
Sound quality and signature: Not transparent. Presentation is upfront. But the amazing thing here is how they've managed to reproduce the Grado headphone sound with these small earphones (the shells are just as big as pills, probably smaller). This piece of work is a minified Grado RS1i. Of course it's not as airy as the RS1i, because IEM.
On lows, mids, and highs: The bass punch is similar to that of the RS1i....